491212591 has 4 divisors (see below), whose sum is σ = 496076184. Its totient is φ = 486349000.

The previous prime is 491212571. The next prime is 491212597. The reversal of 491212591 is 195212194.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 491212591 - 2⁹ = 491212079 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491212597) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2431645 + ... + 2431846.

It is an arithmetic number, because the mean of its divisors is an integer number (124019046).

Almost surely, 2^491212591 is an apocalyptic number.

491212591 is a deficient number, since it is larger than the sum of its proper divisors (4863593).

491212591 is a wasteful number, since it uses less digits than its factorization.

491212591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4863592.

The product of its digits is 6480, while the sum is 34.

The square root of 491212591 is about 22163.3163357833. The cubic root of 491212591 is about 789.0233034787.

The spelling of 491212591 in words is "four hundred ninety-one million, two hundred twelve thousand, five hundred ninety-one".